Printing services Web sites often allow users to access the web site and customize a product with a graphical design. Typically, these printing services sites allow the user to first review uncustomized product images of the various products that are available from the provider, for example business cards, t-shirts, etc. When the user selects a specific product to customize, the sites typically provide online tools allowing the user to provide the text that the user desires to appear on the customized product. The user may also be allowed to either upload a full color image from the user's computer to be incorporated into the product design or to select from a number of decorative designs, images, and other graphic elements that are provided for the user's use by the printing services provider. Images of the user text entries and the user-selected decorative elements, collectively referred to herein as “design images” are combined with the basic product image to create a composite image indicating the appearance of the printed product. When the design is completed to the user's satisfaction, the user can place an order through the site for production of a desired quantity of the corresponding printed product.
Typically, a designer of a graphic design/image intends the image to be immediately visually perceived by those viewing the image. Visual perception is a function of luminence and contrast. As used herein, “luminence” is a photometric measure of the density of luminous intensity in a given direction. Luminance describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. “Contrast”, as used herein, is the difference in visual properties that makes an object (or its representation in an image) distinguishable from other objects and the background. In visual perception of the real world, contrast is determined by the difference in the color and brightness of the object and other objects within the same field of view.
The appearance of an image may be affected by the color of the background on which it is displayed. Specifically, assuming sufficient luminence, if the contrast between the overall image and the background color is low, then the image may not be visually perceived in the manner that the designer intends. Thus, a designer of a graphical image typically designs the image with a specific background color or range of background colors in mind. For example, if the background color is going to be white or a light color, the designer of the image may incorporate mainly dark and/or bright colors, and may avoid or incorporate fewer light colors (including white), to make the image stand out against the white background. Similarly, if the background color is going to be a dark color such as black or navy, the designer of the image may incorporate mainly light and/or bright colors, and may avoid or incorporate fewer dark colors, to make the image stand out against the dark background. The appearance of a printed image is further affected by the degree of contrast between the background color on which the image is displayed or printed and areas of the image that abut the background. For example, an image having white areas that abut non-printed areas of a white t-shirt may not be as visually desirable as an image having only colored areas that abut non-printed areas of the t-shirt. Likewise, when the image to be printed includes areas of darker colors that are printed on a dark t-shirt, the effect of the image may not be as the designer of the image intends. This problem occurs whenever low-contrast colors are used in areas of an image that abut the background.
As illustrated by the preceding examples, it is challenging to create images that may be overlaid on a variety of background colors and still look good (i.e., which are still easily visually perceived by those viewing it). Printing service providers, both retail and online, often carry a large collection of designs that may be printed on various products. For the above described reasons, these designs typically look best when printed or displayed on a particular type of background color (e.g., white or light, or black or dark). However, when customers want to print or display a particular image over a background color that is not ideal to the design, then it is necessary to modify the images so that they can be visually perceived when printed or displayed on the selected background color.
At this time, there is currently no automated way of modifying an image to make it more visually perceptible when printed or displayed on a low-contrast background color. It would be desirable, however, to have such an automated process in order to allow the reuse of existing graphical design content for printing or displaying over a low-contrast background color. A need also exists for an automated technique for creating a set of variant designs/images, given an original design/image, each variant appropriate for printing or displaying on different respective background colors. A need further exists for an image management process which automatically keeps track of a variety of image versions created for different backgrounds and automatically selects the image version associated with a selected background upon selection of a particular background color.